Groove around Last supper carving

[rrrevels]

I was at a friends shop a few days ago and he asked me to help remove the groove around his carving of the Last supper. I tried several things but no matter what I did, ie, cropping outside a rectangle the groove adjusted and was still in the tool path. What am I overlooking? He is trying to get a carving that blends into a rough piece of material and the groove is a distraction. Is there a way to remove the groove that outlines the carving?

[tmerrill]

Russ,

Sent you a PM.

Tim

[rrrevels]

Thanks Tim,

With the help of you and James I finally understand how to get around the problem. I think I couldn't see the forest for the trees so to speak.

Russ

[sawmiller]

sooo the answer is.......

[ailmik]

I'd be interested in knowing the answer as well. I broke a number of endmills until I realised what was going on and changed the cutting angle to 45 degrees.

Kim

[rrrevels]

The answer turned out to be a matter of setting the bounding box tight enugh to keep the bit from dropping to the base level of the artwork. The carving is raised and the edges drop off. By setting the bounding box to the exact edge before the drop the groove is eliminated. Sometimes a little tedious but solved the problem.

Russ

[tmerrill]

One technique is to use the Boundary Vector Offset setting on the Roughing and Finishing toolpath forms.

Once a boundary vector has been created, use a positive Boundary Vector Offset to take the toolpath beyond the edge of the model, or, like in this case, use a negative Boundary Vector Offset to keep the bit on the top of the model.

Tim